USB-C (using the USB 3.1 bus) to VGA to connect external monitors, projectors, TVs, etc. VGA transmits video signal. Supports output up to 1920×1080 (1080p), with flexible support for USB 5G and DisplayPort 1.2 (DP Altmode). Supports VGA with bandwidth of 2.7 Gbps (HBR) and 1.62 Gbps (RBR) per lane.
USB port to connect external peripherals. Connects a USB cable (USB 3.0, 2.0, 1.1) to your computer with USB-C port. Delivers 3A max. power to attached devices with 5 Gbps max. transfer rate. Compatible to all Macs or PCs with USB-C port. USB-C port only for PowerDelivery.
Important Notice: Unplugging the power delivery (PD) from an external power adapter via the LMP USB-C Multiport Adapter can cause the sudden interruption of the power supplied to attached devices (i.e. an external USB HDD). This in return causes attached devices to be unmounted or to loose the connection shortly (the connection is re-established automatically after 2-3 seconds), which may bring about a loss of unsaved data. Therefore, we strongly advise to save all data and/or unmount any attached device before unplugging the PD!
Note: Not compatible with Apple USB SuperDrive
Basically, you can use only iMac (27-inch, Late 2009) and iMac (27-inch, Mid 2010) with a Mini-DisplayPort connection with current Mac with Thunderbolt 3 (USB-C) ports. You need a USB-C to Mini-DisplayPort adapter (e.g. 16134/16138, LMP USB-C to Mini-DisplayPort adapter) or a USB-C dock with Mini-DisplayPort port (e.g. 18641/18645/19009, LMP USB-C Travel Dock 4K 9 Port or 17113/17278/18954, LMP USB-C Compact Dock 4K 8 Port or 17116, LMP USB-C Display Dock 4K 10 Port). Then a Mini-DisplayPort to Mini-DisplayPort cable (8305, LMP Mini-DisplayPort to Mini-DisplayPort cable) must be attached to the dock and the iMac.
With iMac (Mid 2011 to Mid 2014), it is possible to use the iMac as monitor with a Thunderbolt connection only. With newer iMac, a Target Mode with an iMac is not possible anymore.
For further details, see https://support.apple.com/hr-hr/HT204592